make sure ur gain knobs are as high as possible but at the same time not enough to turn the (1)*limiter on (ver. 1,7) or lose sound quality (ver. 1.5)* this will ensure that your recording is loud and crisp when played later. you can test this by recording something and then loading the recording into itch u will see the size of the wave thicker or thinner. u want thicker but just enough that u dont do what I mentioned (1)

The record function can be found here. just click with the mouse "rec"

Recordings are saved to your hard drive, and are available to be used as you would any other audio file on your computer.
Recordings are saved in the following hard drive locations on your computer.
• MyDocuments > MyMusic > Serato > Recording (PC)
• Users > Music > Serato > Recording (Mac)

TIP If you exit Serato DJ without saving your recording, it will be stored in the “Recording temp” folder instead.